How the Smith-Kerns model can help maximize dollar spot control

By Matt Giese, technical services manager, Syngenta, and Paul Koch, Ph.D., University of Wisconsin-Madison

Originally published in Golf Course Industry magazine on May 22, 2019.

With the recent introduction of a model that reliably predicts when dollar spot will first appear in a specific geography, it’s important to familiarize yourself with how it can be best used to treat your course.

Many of the first spring dollar spot applications are based on a calendar day or some combination of calendar day and weather conditions. Until recently, it’s largely been a guessing game.

In 2018, a research paper authored by Damon Smith, Ph.D., associate professor and extension specialist at the University of Wisconsin-Madison, and Jim Kerns, Ph.D., associate professor and extension specialist at NC State University, described a weather-based warning system for when to make fungicide applications to control dollar spot on turfgrass. They tracked dollar spot symptoms over a six-year period at six different turf research locations across the U.S. and found that relative humidity and average daily air temperature were the most predictive conditions for disease development. Using this data, a moving five-day average was inserted into a logistic regression equation, and the Smith-Kerns Dollar Spot Prediction Model was born.

The Smith-Kerns model…Read full article here.